Strapdown Heading Reference SHR-360

Watson heading reference sensors are strap-down devices. This means installation does not require a gimbal. It is equipped with three accelometers that detect level and adjust the heading data appropriately.

Description

The SHR-360 provides heading and sensor information. It includes a high accuracy triaxial fluxgate magnetometer and a triaxial accelerometer. This unit is a “strapdown” or “body-axis” sensor. The sensitive axes of the magnetometer (like the accelerometers) will stay at a constant relationship with the vehicle and move as the vehicle moves. Since the fluxgate sensors rotate with the unit, the unit must use its angle sensors to calculate the rotation back to level. The function is similar to a mechanical gimbal except that the rotations are done using software. The SHR-360 has several advantages over using a traditional gimbal including: no bearings to wear out, no fluid to leak and high shock survivability.

The Watson Industries strapdown solution provides a better magnetic heading than other magnetic heading products using mechanical gimbals. A significant problem with mechanically gimbaled compasses becomes apparent when trying to calibrate the heading sensor in the field. With a strapdown system, the magnetometers are fixed with respect to the vehicle in which it is mounted; Therefore, the constant soft and hard iron field distortions can be fully calibrated out.